import type { Ref } from 'vue'
import { computed, ref, unref } from 'vue'

function pagination<T = any>(list: T[], pageNo: number, pageSize: number): T[] {
  const offset = (pageNo - 1) * Number(pageSize)
  const ret = offset + Number(pageSize) >= list.length ? list.slice(offset, list.length) : list.slice(offset, offset + Number(pageSize))
  return ret
}

export function usePagination<T = any>(list: Ref<T[]>, pageSize: number) {
  const currentPage = ref(1)
  const pageSizeRef = ref(pageSize)

  const getPaginationList = computed(() => {
    return pagination(unref(list), unref(currentPage), unref(pageSizeRef))
  })

  const getTotal = computed(() => {
    return unref(list).length
  })

  function setCurrentPage(page: number) {
    currentPage.value = page
  }

  function setPageSize(pageSize: number) {
    pageSizeRef.value = pageSize
  }

  return { setCurrentPage, getTotal, setPageSize, getPaginationList }
}
